Wire spring and spring structure



Patented July 29, 1941 WIRE SPRING AND SPRING STRUCTURE Jacob Kronheim,Cleveland Heights, hio,,as-

signor to John 0. Lincoln, Scottsdale, Ariz.-

Application May 24, 1938, Serial No. 209,713

2 Claims.

This invention relates to fiat springs of sinuous or similar shape, usedfor seats of upholstered furniture, cushionedautomobile seats or thelike, and more parti arly to the type of springs described in Patent 0.2,047,411 dated July 14th 1936. Springs of this type embody an upperaxially compressible and extensible seating portion, a yielding,rearwardly and downwardly extending supporting means at the front end ofthe seating portion, and a downwardly extending,

Fig. 1 shows a vertical sectional view through a spring structuremounted in the open frame of a cushioned seat, the spring structure em-'bodying springs provided with an elevated front yielding supportingmeans at the rear end of the seating portion. The supporting means ofthe springs are either integrally formedv with the seating portion orrigidly connected to the opposite ends thereof to effect upwardbulgingand longitudinal stretching of the seating portion when a load isplaced thereon.

These springs are assembled to spring structures by individuallymounting the springs with their supporting means upon opposite rails ofan open frame so that all seating portions of the springs are situatedin a plane above the frame, and by interconnecting all seating portionsof the springs to a continuous seating surface, generally to be coveredwith padding and upholstering material and a customary roll front edgeso.

asto insure proper mounting and holding of loose seat cushions.

As well known, construction of a rolledge and its attachment to aseating surfaceis a slow and costly process which necessitatesemployment of highly skilled labor.

The principal object of the present invention is to reduce manufacturingand labor costs in building of upholstered furniture by providingsprings of improved construction and designer!!- bodying at theirfrontseating portions elevated means substantially equal in action tothat of a front r011 edge.

Another objectof the invention is the provision of an improvedwirespring having an elevated seating portion and integral elevated means atthe front of the "seating portion equal in action to that of a frontroll edge. I

In addition, the invention has certain other marked superiorities whichradically distinguish ;it from presently known structures.The-improvements or superior characteristics embodying certain novelfeatures of construction are- -clearly set-forth in the followingspecification and the appended claims; and a preferred form ofembodiment of the invention is hereinafter shown with reference to theaccompanying draw ing formfiig 'p'art of the specification.

In the drawing: 7

edge to permit of proper support of seat cushions on the padded springstructure without use of a special front roll edge; the section beingtaken on line |-I of Fig. 2.

Fig.2 is a cross sectional view through the spring structure and chairbase shown in Fig. 1, the section being taken on line 22 of Fig. 1.

Fig. 3 is a fragmentary vertical sectional view through the rear portionof the chair base and spring structure shown in Fig. l, the sectionbeing taken on line 3-3 of Fig. 2..

Fig. 4 is a perspective view of one of the springs used in theconstruction of the spring structure shown in Fig. 1; and

, Fig. 5 is a perspective view of one of the spring hooks yieldinglytying the rear end of the spring structure to the rear rail of the openframe;

Referring now more particularly to the drawing, reference numeral 2represents the frame of a chair embodying at its bottom portion arectangular open frame 3, the front, rear and side rails 4, 5 and 6 ofwhich are secured to thefront and rear legs 1 and 8 of the frame 2. Openframe 2 has mounted on its front and rear rails 4 and 5 a plurality offlat springsS, made of sinuous-shaped or horizontally corrugated steelwire. These springs each include rearwardly and downwardly inclinedfront and rear'supporting means or'lever arms ill, II respectively,adapted to support the proper seating portion l2 of the spring in anelevated position, which supporting means extend from'the opposite endsof the said seating portion. The front supporting means or supportingarm 10 is looped'at its free end to form two oppositely wound coils I 4and I5, arranged in a plane substantiallyre'ctangular to the plane ofthe seating surface '12, which coils k are of diflerent elasticity, coill4 having less windings than coil l5 and therefore being stifler thansaid latter coil. Preferably, as shown, front lever arm I0 is bent andoffset as at It to prohibit contact of the-coils l4 and I5 with theseating portion I! when a 'load is placed upon said portion. The freeend of coil I5 is extended forwardly of said coil and secured to thefront rail 4 by means of an angular offset l6, metal bracket I! beingused for such purpose.

The. rear supporting means H for the seating portion lZ-is formed as a,curved extension of said surface, curved at its rear portion tosemi-circular shape. This rear supporting means'has thereto, which hook20 is held in proper position on rail 5 by staples 2|.

The above described construction of the rear supporting means ll of thespring 9 materially simplifies manufacturing of said spring and is ofgreat importance for spring seat structures in which the seatingportions of all springs are interconnected to a substantially unitaryseating surface 22 by means of an edge wire 23 and wire braces 24, whichwires are secured to the springs by clips 25, all as shown in thedrawing. In such spring seat structure the movement of the seatingsurface is mainly controlled by the rear supporting means which in thedescribed construction has rather low resistance against forwardmovement of the seating surface when under load. This deficiency in thestructure is overcome by the arrangement of torsion spring means 26which pivotally engage a rearward extension 21 of the edge wire 23. andare secured to the rear rail 5 by means of staples 28. The torsionspring means 28 are made of spring steel wire and embody a coiledportion 29, having extended from its opposite ends a hook-shaped leverarm 30 and an angular resting and attachment arm 3 I which latter issecured to the rail 5 in a manner previously described.

The coil l5 of the front supporting means and the coil IQ of the rearsupporting means effect a substantial reduction of the forwardmovement'of the structure under load. Thus coil I4 has less resiliencythan coil l5, and coil l8, having less resiliency than coil l9, permitof the coils l5 and I!) being contracted to effect a substantiallyvertical downward movement of the seating surface when a load is placedthereon until the elasticity vided with a roll edge to give propersupport to the legs of a person sitting on such structure and to propelysupport the customary seat cushions in such a fashion that the cushionsdo not slip from their support. The present spring structure embodiesmeans .which permit of discarding the edge roll to facilitatemanufacturing at decreased cost. For that purpose the front part of theseating portions l2 of all springs 9 are forwardly and upwardly inclinedas 32 to permit of formation of an elevated front edge on the finishedseat without necessitating the slow and costly attachment of specialmeans for building a roll edge at the front of the spring structure.

Having thus described my invention, what I claim is:

1. A spring for cushioned seats or the like comprising a horizontallycorrugated seating portion including at its front end a ledge upwardlyand outwardly inclined with respect to the axis of said seating portion,a front supporting means'rearwardly and downwardly extended from thefront end of said ledge in inclined relation with respect thereto, andrear supporting means integrally extended from the. rear end of saidseating portion.

2. A spring for cushioned seats or the like comprising a horizontallycorrugated seating portion including at its front end a corrugated ledgeupwardly and outwardly inclined with respect to the axis of said seatingportion, and inclined front and rear supporting means integrallyextended from said seating portion at an inclination with respectthereto.

JACOB KRONHEIM.

